I very much like the concept of $LOCALPATCHES, but it doesn't work
(exactly) as documented.  According to the docs, all files in
$LOCALPATCHES/cat/pkg/ (except *.orig and *.rej) are regarded as diffs 
and applied after the pkgsrc patches.  But then we should either do: 

--- mk/bsd.pkg.patch.mk.orig	2005-08-20 09:24:32.000000000 +0200
+++ mk/bsd.pkg.patch.mk	2005-08-20 09:49:40.000000000 +0200
@@ -201,7 +201,7 @@
 _PKGSRC_PATCHES+=	${PATCHDIR}/patch-*
 .endif
 .if defined(LOCALPATCHES) && exists(${LOCALPATCHES}/${PKGPATH})
-_PKGSRC_PATCHES+=	${LOCALPATCHES}/${PKGPATH}/patch-*
+_PKGSRC_PATCHES+=	${LOCALPATCHES}/${PKGPATH}/*
 .endif
 
 .PHONY: pkgsrc-patch-message do-pkgsrc-patch

or modify the docs so they say that only patch-* files are handled.  

Off-topic: does a similar thing exist for /usr/src ?  

GH